INVESTIGADORES
COMEDI David Mario
artículos
Título:
On the origin of white photoluminescence from ZnO nanocones/porous silicon heterostructures at room temperature
Autor/es:
O. MARÍN; G. GRINBLAT; A. M. GENNARO; M. TIRADO; R. R. KOROPECKI; D. COMEDI
Revista:
SUPERLATTICES AND MICROSTRUCTURES
Editorial:
ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2015 vol. 79 p. 29 - 37
ISSN:
0749-6036
Resumen:
ZnO nanocones were grown on porous silicon (PS) by vapor transport at different temperatures and O2
flow rates without metal nanocatalysts. The ZnO/PS heterostructures
were studied by electron microscopy, and by photoluminescence and
electron resonance (EPR) spectroscopies. Samples emitted strong white
PL, opening potential application for white light illumination. The
photoluminescence spectra were found to include five main components
centered at 1.84, 2.06, 2.30, 2.48 and 3.31 eV. The components at 2.48
and 2.06 eV were related to oxygen vacancies in ZnO, that at 2.3 eV to
Zn vacancies and the one at 1.84 eV to the PS substrate. The low
excitonic emission intensity at 3.31 eV and the observed rough ZnO
nanocone morphology suggest the presence of surface trap states. EPR
shows a g ∼ 2.006 line attributed to Zn divacancies. The absence of the g = 1.96 line, attributed to conduction band electrons, suggests strong carrier depletion.